Susi Hanna, Barrès Benoit, Vale Pedro F, Laine Anna-Liisa
Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), Helsinki FI-00014, Finland.
1] Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK [2] Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK.
Nat Commun. 2015 Jan 8;6:5975. doi: 10.1038/ncomms6975.
Co-infections by multiple pathogen strains are common in the wild. Theory predicts co-infections to have major consequences for both within- and between-host disease dynamics, but data are currently scarce. Here, using common garden populations of Plantago lanceolata infected by two strains of the pathogen Podosphaera plantaginis, either singly or under co-infection, we find the highest disease prevalence in co-infected treatments both at the host genotype and population levels. A spore-trapping experiment demonstrates that co-infected hosts shed more transmission propagules than singly infected hosts, thereby explaining the observed change in epidemiological dynamics. Our experimental findings are confirmed in natural pathogen populations-more devastating epidemics were measured in populations with higher levels of co-infection. Jointly, our results confirm the predictions made by theoretical and experimental studies for the potential of co-infection to alter disease dynamics across a large host-pathogen metapopulation.
多种病原体菌株的共同感染在野外很常见。理论预测，共同感染对宿主内和宿主间的疾病动态都会产生重大影响，但目前相关数据稀缺。在这里，我们使用被两种病原菌白粉菌（Podosphaera plantaginis）菌株单独或共同感染的车前草（Plantago lanceolata）普通栽培种群，发现在宿主基因型和种群水平上，共同感染处理组的疾病患病率最高。一项孢子捕获实验表明，共同感染的宿主比单独感染的宿主释放出更多的传播繁殖体，从而解释了观察到的流行病学动态变化。我们的实验结果在自然病原体种群中得到了证实——在共同感染水平较高的种群中测量到了更具毁灭性的流行病。总体而言，我们的结果证实了理论和实验研究对于共同感染改变大型宿主 - 病原体集合种群中疾病动态的潜力所做的预测。
